Method of making an absorbent article including liquid containment beams

ABSTRACT

A method of making an absorbent article includes providing a liquid containment beam having longitudinal ends and attachment and free edges that extend between the longitudinal ends. The attachment edge is bonded to an interior surface of the absorbent article and a bottom surface of the containment beam is adapted to lie against but be unadhered to the interior surface. The resulting containment beam can pivot about an axis defined by the attachment edge in response to lateral compression of the article, extension or contraction of elastic members, absorption of liquids, or a combination of these factors.

This application is a continuation of application Ser. No. 08/485,221entitled "METHOD OF MAKING AN ABSORBENT ARTICLE INCLUDING LIQUIDCONTAINMENT BEAMS" and filed in the U.S. Patent and Trademark Office onJun. 7, 1995, now abandoned. The entirety of this Application is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a method of making articles forabsorbing body fluids. More particularly, the invention pertains to amethod of making an absorbent article including one or more containmentbeams that absorb liquid and impede liquid flow.

Disposable absorbent articles such as incontinence undergarments,diapers, feminine products, or the like have commonly included a liquidpermeable bodyside liner, a liquid impermeable moisture barrier, and agenerally flat absorbent material disposed between the bodyside linerand the moisture barrier. A substantial portion of the absorbentmaterial is routinely positioned in the crotch region of the articlewhere it is likely to directly receive insults of liquid. Because theabsorbent material tends to swell upon taking in the first insult ofliquid, however, the amount of void space in the crotch region availableto receive subsequent insults is substantially reduced.

It has also been common for disposable absorbent articles to includeelastic components, such as leg elastics, waist elastics, and/or elasticfastening devices. The function of these elastic components has been toimprove the fit of the absorbent article about the wearer, and therebyenhance the containment of waste materials. Typically, however, theabsorbent material is fully bonded or otherwise held immobile betweenthe bodyside liner and the moisture barrier. Consequently, the impact ofelastic components has been limited to sealing the periphery of theabsorbent article against the body of the wearer, rather thancontrolling the shape of the article when it is worn.

Therefore, what is lacking and needed in the art is an efficient methodof making an absorbent article that maintains void space for multipleinsults of liquid and that has an absorbent structure which promotes aproduct shape that enhances liquid containment.

SUMMARY OF THE INVENTION

In response to the discussed deficiencies in the prior art, a new methodof making an absorbent article has been developed. The method results inan absorbent article that readily assumes a bucket shape when worn toaid in collecting liquids. Additionally, the method of selecting andarranging of the components of the absorbent article provides sufficientvoid space in an acquisition zone of the article to accept anddistribute multiple insults of liquid.

In one aspect, the present invention concerns a method of making anabsorbent article comprising the steps of: providing a garment shellcomprising a moisture barrier and defining an interior surface;providing a liquid containment beam comprising an absorbent material,the liquid containment beam having: longitudinal ends which definetherebetween a length dimension; opposite attachment and free edgeswhich extend between the longitudinal ends, the attachment and freeedges defining therebetween a width dimension; and opposite top andbottom surfaces which define therebetween a thickness dimension, a ratioof the width dimension to the thickness dimension being at least about3:1; and bonding the attachment edge to the interior surface, the bottomsurface being adapted to lie against the interior surface, and theliquid containment beam being adapted to pivot about an axis defined bythe attachment edge.

In another aspect, the present invention concerns a method of making anabsorbent article comprising the steps of: providing a garment shellcomprising a moisture barrier and defining an interior surface;providing first and second liquid containment beams, at least one of thefirst and second liquid containment beams comprising an absorbentmaterial, each liquid containment beam having: longitudinal ends;opposite attachment and free edges which extend between the longitudinalends; and opposite top and bottom surfaces; and bonding each attachmentedge to the interior surface, the bottom surface of the firstcontainment beam being adapted to lie against the interior surface, thebottom surface of the second containment beam being adapted to lieagainst the top surface of the first containment beam, and each of theliquid containment beams being adapted to pivot about an axis defined byits attachment edge.

In yet another aspect, the present invention concerns a method of makingan absorbent article comprising the steps of: providing a garment shellcomprising a moisture barrier and defining an interior surface;providing first and second inner liquid containment beams comprising anabsorbent material; providing first and second outer liquid containmentbeams, each of the inner and outer liquid containment beams having:longitudinal ends; opposite attachment and free edges which extendbetween the longitudinal ends; and opposite top and bottom surfaces; andbonding the attachment edge of each of the inner and outer liquidcontainment beams to the interior surface, the bottom surface of each ofthe inner containment beams being adapted to lie against the interiorsurface, the bottom surface of each of the outer containment beams beingadapted to lie against the top surface of one of the inner containmentbeams, and each of the liquid containment beams being adapted to pivotabout an axis defined by its attachment edge.

In still another aspect, the present invention concerns a method ofmaking an absorbent article comprising the steps of: providing a garmentshell comprising a moisture barrier formed of a vapor permeable andsubstantially liquid impermeable material, the garment shell definingopposite end edges, opposite side edges extending between the end edges,a first waist region, a second waist region, and a crotch regionpositioned between and interconnecting the first and second waistregions, the crotch region including an acquisition zone spaced inwardfrom the side edges; providing an acquisition/distribution material andbonding the acquisition/distribution material to the moisture barrier inthe acquisition zone; providing desiccant particles and positioning thedesiccant particles between the moisture barrier and theacquisition/distribution material; providing first and second liquidcontainment beams, each liquid containment beam comprising an absorbentmaterial and having: longitudinal ends; opposite attachment and freeedges which extend between the longitudinal ends; and opposite top andbottom surfaces; and bonding the attachment edge of each liquidcontainment beam to the garment shell between the acquisition zone oneof the side edges, each bottom surface being adapted to lie against theacquisition/distribution material, and each liquid containment beambeing adapted to pivot about an axis defined by its attachment edge.

Numerous features and advantages of the present invention will appearfrom the following description. In the description, reference is made tothe accompanying drawings which illustrate preferred embodiments of theinvention. Such embodiments do not represent the full scope of theinvention. Reference should therefore be made to the claims herein forinterpreting the full scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 representatively shows a perspective view of a disposableabsorbent article according to the present invention.

FIG. 2 representatively shows a plan view of portions of the disposableabsorbent article shown in FIG. 1, taken from the bodyside of theabsorbent article in a stretched and laid flat condition and withportions broken away for purposes of illustration.

FIG. 3 representatively shows an enlarged section view taken generallyfrom the plane of the line 3--3 in FIG. 2.

FIG. 4 representatively shows an enlarged section view taken generallyfrom the plane of the line 4--4 in FIG. 2.

FIG. 5 representatively shows a transverse section view of the absorbentarticle of FIG. 1 while positioned to simulate the article being worn.

FIG. 6 representatively shows a section view similar to FIG. 5, althoughillustrating the absorbent article after liquid has been absorbed.

FIG. 7 representatively shows a plan view of portions of an alternativeabsorbent article according to the invention, taken from the bodyside ofthe absorbent article in a stretched and laid flat condition and withportions broken away for purposes of illustration.

FIG. 8 representatively shows an enlarged section view taken generallyfrom the plane of the line 8--8 in FIG. 7.

FIG. 9 representatively shows an enlarged section view similar to FIG.8, but illustrating an alternative embodiment of the invention.

FIG. 10 representatively shows an enlarged section view similar to FIG.8, but illustrating another alternative embodiment of the invention.

FIG. 11 representatively shows a plan view of portions of a furtheralternative absorbent article according to the invention, taken from thebodyside of the absorbent article in a stretched and laid flat conditionand with portions broken away for purposes of illustration.

FIG. 12 representatively shows an enlarged section view taken generallyfrom the plane of the line 12--12 in FIG. 11.

DEFINITIONS

Within the context of this specification, each term or phrase below willinclude the following meaning or meanings:

(a) "Bonded" refers to the joining, adhering, connecting, attaching, orthe like, of two elements. Two elements will be considered to be bondedtogether when they are bonded directly to one another or indirectly toone another, such as when each is directly bonded to intermediateelements.

(b) "Disposable" includes being disposed of after use and not intendedto be washed and reused.

(c) "Disposed," "disposed on," "disposed with," "disposed at," "disposednear" and variations thereof are intended to mean that one element canbe integral with another element, or that one element can be a separatestructure bonded to or placed with or placed near another element.

(d) "Elastic," "elasticized" and "elasticity" mean that property of amaterial by virtue of which it tends to recover its original size andshape after removal of a force causing a deformation.

(e) "Elastomeric" refers to a material or composite which can beelongated by at least 25 percent of its relaxed length and which willrecover, upon release of the applied force, at least 10 percent of itselongation. It is generally preferred that the elastomeric material orcomposite be capable of being elongated by at least 100 percent, morepreferably by at least 300 percent, of its relaxed length and recover,upon release of an applied force, at least 50 percent of its elongation.

(f) "Extension," "extend" and "extended" mean the change in length of amaterial due to stretching, expressed in units of length.

(g) "Fabrics" is used to refer to all of the woven, knitted and nonwovenfibrous webs.

(h) "Flexible" refers to materials which are compliant and which willreadily conform to the general shape and contours of the wearer's body.

(i) "Force" includes a physical influence exerted by one body on anotherwhich produces acceleration of bodies that are free to move anddeformation of bodies that are not free to move.

(j) "Hydrophilic" describes fibers or the surfaces of fibers which arewetted by the aqueous liquids in contact with the fibers. The degree ofwetting of the materials can, in turn, be described in terms of thecontact angles and the surface tensions of the liquids and materialsinvolved. Equipment and techniques suitable for measuring thewettability of particular fiber materials or blends of fiber materialscan be provided by a Cahn SFA-222 Surface Force Analyzer System, or asubstantially equivalent system. When measured with this system, fibershaving contact angles less than 90° are designated "wettable" orhydrophilic, while fibers having contact angles greater than 90° aredesignated "nonwettable" or hydrophobic.

(k) "Integral" is used to refer to various portions of a single unitaryelement rather than separate structures bonded to or placed with orplaced near one another.

(l) "Inward" and "outward" refer to positions relative to the center ofan absorbent garment, and particularly transversely and/orlongitudinally closer to or away from the longitudinal and transversecenter of the absorbent garment.

(m) "Layer" when used in the singular can have the dual meaning of asingle element or a plurality of elements.

(n) "Liquid communication" means that liquid such as urine is able totravel from one layer to another.

(o) "Liquid impermeable" when used to describe a layer or laminate meansthat liquid such as urine will not pass through the layer or laminateunder ordinary use conditions in a direction generally perpendicular tothe plane of the layer or laminate at the point of liquid contact.

(p) "Member" when used in the singular can have the dual meaning of asingle element or a plurality of elements.

(q) "Nonwoven web" means a web of material which is formed without theaid of a textile weaving or knitting process.

(r) "Operatively joined" and "operatively connected," with reference tothe attachment of an elastic member to another element, means that theelastic member when attached to or connected to the element, or treatedwith heat or chemicals, by stretching, or the like, gives the elementelastic properties; and with reference to the attachment of anon-elastic member to another element, means that the member and elementcan be attached in any suitable manner that permits or allows them toperform the intended or described function of the joinder. The joining,attaching, connecting or the like can be either directly, such asjoining either member directly to an element, or can be indirectly bymeans of another member disposed between the first member and the firstelement.

(s) "Stretch bonded" refers to an elastic member being bonded to anothermember while the elastic member is extended at least about 25 percent ofits relaxed length. Desirably, the term "stretch bonded" refers to thesituation wherein the elastic member is extended at least about 100percent, and more desirably at least about 300 percent, of its relaxedlength when it is bonded to the other member.

(t) "Stretch bonded laminate" refers to a composite material having atleast two layers in which one layer is a gatherable layer and the otherlayer is an elastic layer. The layers are joined together when theelastic layer is in an extended condition so that upon relaxing thelayers, the gatherable layer is gathered.

(u) "Unadhered" refers to an absence of bonds of sufficient strength towithstand the forces typically encountered during ordinary wearing ofthe article.

These terms may be defined with additional language in the remainingportion of the specification.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1-4, an absorbent article formed according tothe invention is shown for purposes of illustration as a disposableundergarment 20 for adult incontinence. The invention may also beembodied in other types of absorbent articles, such as other adult careproducts, reusable absorbent articles, disposable diapers, trainingpants, feminine hygiene products, other personal care or health caregarments, or the like.

In general, the undergarment 20 includes a garment shell 45 and aplurality of containment beams 50. Each containment beam 50 is bondedalong an attachment edge 62 to an interior surface 46 of the garmentshell 45 so that the containment beam is pivotable about and axisdefined by the attachment edge in response to lateral compression of thegarment shell, extension or contraction of elastic members, absorptionof liquids, or a combination of these factors. The containment beams 50are desirably the principle means by which the undergarment 20 retainsliquids.

To facilitate the undergarment 20 having a bucket shape, the containmentbeams 50 are transversely spaced from the longitudinal center line 22 ofthe garment shell 45 and located near leg elastic members 48. Further, arelatively flexible material 51 for acquiring and/or distributing liquidis desirably located between the containment beams 50. To promotecomfort, the containment beams 50 desirably have a width to thicknessratio of at least about 3:1, and more particularly at least about 5:1.In particular embodiments, pairs of containment beams 50 are provided ina shingled arrangement, and further, the absorbent structures 52 withinthe containment beams may be in a shingled arrangement as well.Absorbent articles employing containment beams 50 have been tested andfound to have a beneficial impact on reducing leakage compared topresent commercial undergarments.

The illustrated undergarment 20 defines a longitudinal axis or centerline and a transverse axis or center line, represented by arrows 22 and24 in FIG. 2. The undergarment 20 has opposite, front and backlongitudinal end edges 26 and 27, and first and second longitudinal sideedges 28 and 29 that extend between the longitudinal end edges. Theundergarment 20 includes a first or front waist region 30, a second orback waist region 32, and an intermediate, crotch region 34 positionedbetween and interconnecting the front and back waist regions. The outeredges of the undergarment 20 define a periphery 36 in which thelongitudinally extending side margins are designated 38 and thelaterally extending end margins are designated 39. The end edges 26 and27 and side edges 28 and 29 are shown as generally straight, butoptionally, may be curvilinear and contoured.

The front waist region 30 is contiguous with the front end edge 26 andextends longitudinally inward therefrom toward the transverse centerline 24 of the undergarment 20. The back waist region 32 is contiguouswith the back end edge 27 and extends longitudinally inward therefromtoward the transverse center line. The waist regions 30 and 32 comprisethose upper portions of undergarment 20 which, when worn, wholly orpartially cover or encircle the waist or mid-lower torso of the wearer.The intermediate, crotch region 34 comprises that portion ofundergarment 20 which, when worn, is positioned between the legs of thewearer and covers the lower torso of the wearer. Thus, the crotch region34 is the area where insults of urine typically occur in theundergarment or other disposable absorbent article.

The illustrated undergarment 20 includes a substantially liquidimpermeable moisture barrier 40 and a substantially liquid permeablebodyside liner 44. The moisture barrier 40 and bodyside liner 44 arebonded together, such as by ultrasonic bonds, thermal bonds, adhesives,or other suitable means. The peripheries of the moisture barrier 40 andthe bodyside liner 44 form the side and end margins 38 and 39 of theundergarment 20. Conventional absorbent products typically employ someform of absorbent structure between the layers functioning as themoisture barrier and the bodyside liner. In the present undergarment 20,however, the liquid containment beams 50 minimize or eliminate the needfor such an absorbent structure. Nevertheless, in particular embodimentsof the present invention, it may be desirable to include a tissue layeror a thin layer of cellulose fibers between the moisture barrier 40 andbodyside liner 44 in areas where there are no containment beams 50.

The moisture barrier 40 desirably comprises a material that is formed ortreated to be liquid impermeable. Alternatively, the moisture barrier 40may comprise a liquid permeable material and other suitable means (notshown) may be provided to impede liquid movement away from the crotchregion 34 and the liquid containment beams 50. The moisture barrier 40may also be vapor permeable, such that vapors encountered during use ofthe absorbent garment are able to pass through the material underordinary use conditions, over either all or part of its surface area.

The moisture barrier 40 may comprise a single layer of material or alaminate of two or more separate layers of material. Suitable moisturebarrier materials include films, wovens, nonwovens, laminates of films,wovens, and/or nonwovens, or the like. For example, the moisture barrier40 may comprise a thin, substantially liquid impermeable web or sheet ofplastic film such as polyethylene, polypropylene, polyvinyl chloride orsimilar material. The moisture barrier material may be transparent oropaque and have an embossed or matte surface. One particular materialfor the moisture barrier 40 is a polyethylene film that has a nominalthickness of about 0.025 millimeter and a systematic matte embossedpattern, and that has been corona treated on both sides.

The bodyside liner 44 provides a soft, nonirritating surface against theskin of the wearer. Accordingly, a separate layer functioning as abodyside liner may not be needed if the moisture barrier 40 issufficiently soft and nonirritating to be positioned against the skin.If used, the bodyside liner 44 may be formed of either a liquidpermeable material or, if no layers functioning as absorbent or liquidhandling layers are disposed beneath the body liner, a liquidimpermeable material. Suitable bodyside liners 44 may comprise anonwoven web or sheet of wet strength tissue paper, a spunbonded,meltblown or bonded-carded web composed of synthetic polymer filamentsor fibers, such as polypropylene, polyethylene, polyesters or the like,or a web of natural polymer filaments or fibers such as rayon or cotton.In addition, the bodyside liner 44 is desirably nonelastic and may betreated with a surfactant to aid in liquid transfer. In a particularembodiment of the invention, the bodyside liner 44 comprises a nonwoven,spunbond polypropylene fabric composed of about 2.8 to 3.2 denier fibersformed into a web having a basis weight of about 22 gram per squaremeter (gsm) and density of about 0.06 gm/cc. The fabric is surfacetreated with about 0.28 weight percent of a surfactant commerciallyavailable from Union Carbide Chemicals and Plastics Company, Inc. ofDanbury, Conn., U.S.A., under the trade designation Triton X-102.

The portions of the undergarment 20 including the moisture barrier 40,bodyside liner 44 if used, and components therebetween, will be referredto as a garment shell and will be designated reference numeral 45. Thegarment shell 45, shown in a stretched and laid flat condition in FIG.2, is illustrated as having a rectangular periphery 36. Of course, thegarment shell 45 may optionally be hourglass-shaped, I-shaped, T-shaped,or irregularly-shaped. The garment shell 45 has an interior surface 46which is intended to face the wearer when the undergarment 20 is worn,and an opposite exterior surface 47. In the illustrated embodiment, theinterior surface 46 is generally provided by the bodyside liner 44 andthe exterior surface 47 is generally provided by the moisture barrier40.

Desirably although not necessarily, the garment shell 45 also includesleg elastic members 48 to draw and hold the side margins 38 of theundergarment 20 against the legs of the wearer and form a sealtherewith. The elongated leg elastic members 48 are longitudinallyorientated in each side margin 38, extending toward the front and backend edges 26 and 27. The leg elastic members 48 are positioned in theillustrated embodiment between the moisture barrier 40 and the bodysideliner 44. Using ultrasonic bonds, adhesives, thermal bonds, or othersuitable means, the leg elastic members 48 are operatively joined in astretched condition to the moisture barrier 40, the bodyside liner 44,or both, in either a straight or a curved shape. Alternatively, the legelastic members 48 may be operatively joined in a relaxed state to agathered portion of the moisture barrier 40, the bodyside liner 44, orboth.

The leg elastic members 48 may be formed of a dry-spun coalescedmultifilament elastomeric thread sold under the tradename LYCRA andavailable from E. I. Du Pont de Nemours and Company. Alternately, theelastic members 48 may be formed of other typical elastics utilized inthe undergarment-making art, such as a thin ribbon of natural rubber, astretch bonded laminate material comprising a prestretched elasticmeltblown inner layer sandwiched between and bonded to a pair ofspunbond polypropylene nonwoven webs, or the like. Elasticity could alsobe imparted to the absorbent article by extruding a hot melt elastomericadhesive between the moisture barrier 40 and the liner 44. Othersuitable elastic gathering means are disclosed in U.S. Pat. No.4,938,754 to Mesek and U.S. Pat. No. 4,388,075 to Mesek et al.

In one aspect of the invention, the liquid retention capacity of theundergarment 20 is principally provided by a number of liquidcontainment beams 50. The undergarment 20 shown in FIGS. 1-4 includesfour containment beams 50, although the particular number of containmentbeams may vary. For ease of reference, the containment beams 50 will bereferred to individually as a first inner containment beam 50A, a secondinner containment beam 50B, a first outer containment beam 50C, and asecond outer containment beam 50D. The undergarment 20 also desirablyincludes material, referred to as an acquisition/distribution material51, that is positioned between the inner containment beams 50A and 50Band adapted to initially take in liquids quickly and/or transport theliquids to the containment beams 50. The acquisition/distributionmaterial 51 is adapted by capillary attraction, hydrophilic properties,or other suitable means to take in and then release the liquid to thecontainment beams 50.

Each of the illustrated containment beams 50 is desirablynon-elastomeric and comprised of an absorbent structure 52 positionedwithin a portion of a support layer 54 FIGS. 3 and 4. The absorbentstructures 52 comprise materials adapted to absorb and retain liquidwaste. The absorbent structures 52 may comprise various absorbentmaterials, such as an air-formed batt of cellulosic fibers (for example,wood pulp fluff), a coform material composed of a mixture of cellulosicfibers and synthetic polymer fibers, other air-laid composites, or thelike. Polymer fibers may be incorporated, for example, in the mannerdescribed in U.S. Pat. No. 5,227,107 issued Jul. 13, 1993, to Dickensonet al. The absorbent structures 52 may also comprise compounds such asorganic or inorganic high-absorbency materials, which are typicallycapable of absorbing at least about 15 and desirably more than 25 timestheir weight in water. Suitable swellable high-absorbency materials aredescribed in U.S. Pat. No. 4,699,823 issued Oct. 13, 1987, toKellenberger et al. and U.S. Pat. No. 5,147,343 issued Sep. 15, 1992, toKellenberger, which are incorporated herein by reference.High-absorbency materials are available from various commercial vendors,such as Dow Chemical Company, Hoechst Celanese Corporation, and AlliedColloids, Inc. The absorbent structures 52 may also include tissuelayers or acquisition or distribution layers to help maintain theintegrity of fibrous absorbents or transport liquids (not shown). Theindividual containment beams 50 may have identical absorbent structures52 or absorbent structures that differ from one another in density,basis weight, materials, material amounts, or other suchcharacteristics.

Each of the absorbent structures 52 is almost completely enclosed withina portion of the support layer 54. The support layer 54 functions tocontain an absorbent structure 52 while also allowing liquids to passthrough to the absorbent structure. The support layer 54 may alsofunction to distribute liquids along and around the absorbent structures52. The support layer 54 is bonded at spaced locations to the bodysideliner 44, thereby bonding each of the containment beams 50 to theinterior surface 46 of the garment shell 45. As best shown in FIG. 3,the support layer 54 may comprise one integral layer extending acrosssubstantially the entire width of the garment shell 45, with different,transversely spaced portions wrapping each of the absorbent structures52. The support layer 54 is bonded to the bodyside liner 44 adjacent oneof the long edges of each absorbent structure 52. Alternatively, aseparate support layer 54 may be provided for each absorbent structure52 (not shown), or no support layer need be used (FIG. 10).

The support layer 54 is desirably formed of a liquid permeable materialthat is soft and does not irritate the skin of the wearer. The supportlayer 54 may comprise a woven, knit or nonwoven web. Suitable nonwovenwebs include spunbonded, meltblown or bonded-carded webs composed ofsynthetic polymer filaments or fibers, such as polypropylene,polyethylene, polyesters or the like, or webs of natural polymerfilaments or fibers such as rayon or cotton. The support layer 54 mayalso be treated with a surfactant to aid in liquid transfer to theabsorbent structures 52. In particular embodiments, the support layer 54comprises a single layer construction made from a 20.3 gsm (0.6 osy)thermally bonded web with 100 percent 3 denier polyethylene sheath andpolyester core bicomponent staple fibers available from BASF Corporationof Enka, N.C., U.S.A.

Each containment beam 50 is a generally planar structure having oppositelongitudinal ends 60 which define therebetween a length dimension (FIG.2). Each of the containment beams 50 also has an attachment edge 62 andan opposite free edge 63 which extend between the longitudinal ends 60(FIGS. 2 and 3). A width dimension of each containment beam 50 isdefined between the attachment and free edges 62 and 63. The width andlength dimensions of each containment beam 50 dictate the size ofopposite top and bottom surfaces 64 and 65 of each containment beam 50.The distance between the top and bottom surfaces 64 and 65 defines athickness dimension of each containment beam 50.

The containment beams 50 are bonded to the garment shell 45 so that thecontainment beams are moveable in response to lateral compression of thegarment shell, extension or contraction of the leg elastic members 48,absorption of liquids, or a combination of these factors. One particularmethod of bonding the containment beams 50 to the garment shell 45 isillustrated in detail in the transverse section view of FIG. 3. Theattachment edge 62 of the first inner containment beam 50A is bonded tothe interior surface 46. More particularly, the support layer 54 iswrapped around the absorbent structure 52 and bonded to the bodysideliner 44 at a bond region 66A. Adhesives, ultrasonic bonds, thermalbonds, mechanical bonds or other suitable means may used to bond thecontainment beams 50 to the interior surface 46. The location at whichthe containment beam 50A is attached to the interior surface 46 definesthe attachment edge 62. As a result of this method of attachment and theshape of the containment beam 50A, the bottom surface 65 of the firstinner containment beam 50A can lay down flat against theacquisition/distribution material 51. Desirably, the bottom surface 65and the free edge 63 are unadhered to the acquisition/distributionmaterial 51 so that the first inner containment beam 50A is adapted tomove relative to the garment shell 45. More precisely, the containmentbeam 50A is adapted to pivot about an axis defined by its attachmentedge 62. While the free edges 63 are illustrated as positioned closer tothe longitudinal center line 22 than the attachment edges 62, it shouldbe apparent that the orientation of the containment beams 50 could bereversed so that the free edges are transversely outward of theattachment edges when positioned flush against the interior surface 46.

The first outer containment beam 50C is attached in a similar manner,with the attachment edge 62 bonded to the interior surface 46 at a bondregion 66C (FIG. 3). The bond region 66C for the first outer containmentbeam 50C is located between the bond region 66A for the first innercontainment beam 50A and the first side edge 28. Attachment of the firstouter containment beam 50C in this way allows the bottom surface 65 ofthe first outer containment beam 50C to lay down flat against the topsurface 64 of the first inner containment beam 50A. The bottom surface65 and the free edge 63 of the first outer containment beam 50C aredesirably unadhered to the first inner containment beam 50A so that thefirst outer containment beam 50C is adapted to move relative to thegarment shell 45, and in particular pivot about an axis defined by itsattachment edge 62.

As suggested in FIG. 3, the second inner and outer containment beams 50Band 50D are bonded to the interior surface 46 of the garment shell 45 ina similar manner. The bond regions 66B and 66D where the attachmentedges 62 of the second inner and outer containment beams 50B and 50D arebonded to the bodyside liner 44 lie between the longitudinal center line22 and the second side edge 29. If desired, the support layer 54 may bebonded to the bodyside liner 44 and/or moisture barrier 40 transverselyoutward of bond regions 66C and 66D and between the bond regions 66. Theinner containment beams 50A and 50B are considered to lie against theinterior surface 46 if they are directly contacting the layer formingthe interior surface, such as the bodyside liner 44, or if they aredirectly contacting a layer, such as acquisition/distribution layer 51,which is bonded to the layer forming the interior surface.

With reference to FIGS. 1, 2 and 4, end seals 68 may optionally beattached to the interior surface 46. The illustrated end seals 68 arebonded over the longitudinal ends 60 of the containment beams 50 tomaintain the bottom surfaces 65 of the inner containment beams 50A and50B at the longitudinal ends 60 against the interior surface 46 and tomaintain the bottom surfaces 65 of the outer containment beams 50C and50D at the longitudinal ends 60 against the inner containment beams 50Aand 50B. The end seals 68 may be formed of any woven or nonwovenmaterial, either liquid permeable or liquid impermeable, and which isdesirably soft and not irritating against the skin of the wearer. Asdiscussed in relation to the embodiment of FIG. 11, the end seals 68 maybe liquid impermeable and function to limit longitudinal migration ofliquid. The end seals 68 may be bonded to the interior surface 46 usingadhesives, ultrasonic bonds, thermal bonds, mechanical bonds, or othersuitable means.

The spacing between the free edges 63 of the inner containment beams 50Aand 50B is a function of the width of the containment beams 50A and 50Band location of their bond regions 66A and 66B. The distance between thefree edges 63 of the inner containment beams 50A and 50B, measured whenthe undergarment 20 is in a stretched and laid flat condition and thecontainment beams are directed inward against the interior surface 46,is desirably from 0 to about 10 centimeters (cm), and more desirablyfrom about 0 to about 4 cm. Alternatively, the distance between the freeedges 63 may be greater for larger products. Still alternatively, thefree edges 63 of the inner containment beams 50A and 50B may touch oroverlap one another (not shown). The containment beams 50 may beattached so that they are parallel, curved or perpendicular to thelongitudinal axis 22 of the undergarment 20.

In one aspect of the invention, the shape of the containment beams 50 isselected to enhance comfort when the undergarment 20 is worn. Becausethe containment beams 50 are desirably attached to the interior surface46 at a substantial relative distance from the longitudinal center line22, it has been recognized that the containment beams 50 shoulddesirably possess a ratio of the width dimension to the thicknessdimension of at least about 3:1, so as not to be uncomfortable,particularly when the wearer is sitting. More desirably, the ratio ofthe width dimension to the thickness dimension is at least about 5:1,and particularly from about 8:1 to about 10:1, for enhanced comfort. Ina particular embodiment, the containment beams 50 have a maximum widthdimension of about 2 cm and a maximum thickness dimension of about 0.4cm, resulting in a width to thickness ratio of 5:1. The length of thecontainment beams 50 is suitably from about 25 to 100 percent of thelength of the undergarment 20. The width of the containment beams 50 maybe constant over the length of the containment beams as illustrated, oralternatively the width may vary, such as by becoming wider toward eachlongitudinal end 60 (not shown).

In another aspect of the invention, the pivotable containment beams 50are positioned in a shingled arrangement to further improve comfort. Theouter containment beams 50C and 50D are adapted to lay against the topsurfaces 64 of the inner containment beams 50A and 50B, respectively.Further, the attachment edges 62 of the outer containment beams 50C and50D are desirably spaced from the attachment edges 62 of the innercontainment beams 50A and 50B by from 0 to about 100 percent of thewidth of the outer containment beams 50C and 50D. More particularly, theattachment edges 62 of the outer containment beams 50C and 50D arespaced from the attachment edges of the inner containment beams 50A and50B by from about 25 to about 60 percent of the width of the outercontainment beams. This shingled arrangement of the containment beams 50provides a gradual increase and then decrease in thickness of theundergarment 20 in the transverse direction, for improved comfort.

The acquisition/distribution material 51 helps to decelerate and diffusesurges of liquid that may be introduced into the crotch region 34 of thegarment shell 45. In the illustrated embodiment, for example, theacquisition/distribution material 51 is located on and bonded directlyto the portion of the support layer 54 that is located between the innercontainment beams, which in turn is located on and bonded directly tothe interior surface 46 of the garment shell 45. Alternatively, theacquisition/distribution material 51 may be interposed between thesupport layer 54 and the bodyside liner 44 or interposed betweenbodyside liner 44 and moisture barrier 40.

The acquisition/distribution material 51 may comprise any woven ornonwoven web adapted to quickly take in and/or transport liquids. Forexample, the acquisition/distribution material 51 may comprise anonwoven web such as a spunbonded, meltblown or bonded-carded webcomposed of synthetic polymer filaments or fibers, such aspolypropylene, polyethylene, polyesters or the like, or a web of naturalpolymer filaments or fibers such as rayon or cotton. Theacquisition/distribution material may comprise a nonwoven fibrous webcomposed of a substantially hydrophobic material. In one particularembodiment, the acquisition/distribution material comprises a 100 gsm(3.0 osy) web formed of a homogeneous blend of 60 percent 3 denierpolyethylene/polypropylene fibers available under the trade designationESC-HR5 from Chisso Corporation of Osaka, Japan and 40 percent 6 denierpolyester fibers available under the trade designation T-295 fromHoechst Celanese Corporation of Sommerville, N.J., U.S.A., and bonded at129 degrees Celsius (265 degrees Fahrenheit) for 1.8 seconds. Othersuitable configurations of the acquisition/distribution material 51 aredescribed in U.S. Pat. No. 5,192,606 issued Mar. 9, 1993, to D. Proxmireet al.; U.S. Pat. No. 4,798,603 issued Jan. 17, 1989, to S. Meyer etal.; U.S. Pat. No. 5,364,382 issued Nov. 15, 1994, to M. Latimer et al.;U.S. patent application Ser. No. 757,760 of W. Hanson et al. filed Sep.11, 1991 (Attorney docket No. 9922); U.S. patent application Ser. No.206,986 of C. Ellis and D. Bishop, entitled FIBROUS NONWOVEN WEB SURGELAYER FOR PERSONAL CARE ABSORBENT ARTICLES AND THE LIKE, and filed Mar.4, 1994 (Attorney docket No. 11,256); and U.S. patent application Ser.No. 206,069 of C. Ellis and R. Everett, entitled IMPROVED SURGEMANAGEMENT FIBROUS NONWOVEN WEB FOR PERSONAL CARE ABSORBENT ARTICLES ANDTHE LIKE, and filed Mar. 4, 1994 (Attorney docket No. 11,387); thedisclosures of which are hereby incorporated by reference.

The attachment system in the illustrated embodiment includes a pair ofstrap members 70 and fastening components to releasably attach the strapmembers to the front and back waist regions 30 and 32. The fasteningcomponents include a retainer 72 in the form of a button bonded at eachend of each strap member 70. The retainers 72 may be releasably securedin slits 74 formed in the garment shell 45. When the undergarment 20 ispositioned on the wearer, the straps 70 extend between the front andback slits 74 so that the retainers 72 may be releasably secured in theslits. This attachment system is described in U.S. Pat. No. 4,315,508 toBolick, which is incorporated herein by reference. Optionally, othertypes of attachment systems, such as tapes, stretchable side panels,self-engaging geometric shaped materials, such as hooks, loops, bulbs,mushrooms, arrowheads, balls on stems, or the like, may be employed.

The strap members 70 (FIG. 1) are each generally rectangular strips ofmaterial, which is desirably an elastic material capable of stretchingto approximately 2.8 to 3 times its relaxed length. The strap members 70desirably have a length from about 15 to about 41 centimeters (cm.), anda width from about 1 to about 5 cm. For example, each strap member 70may be 28 cm. long and 2.5 cm. wide. The cut ends of the strap members70 may be bonded by ultrasonics, adhesives or other suitable means toprevent raveling.

In use, the undergarment 20 is positioned on the body of the wearer andsecured in position using the attachment system. A transverse sectionview of the undergarment 20 against a contoured surface 76, whichrepresents the legs of a wearer, is shown in FIG. 5 to simulate theposition of the undergarment during use. The interaction of the strapmembers 70 (FIG. 1) and the leg elastic members 48 cause the sidemargins 38 to be drawn against the legs of the wearer. It should also benoted that lateral compression of the undergarment 20 between the legsand extension of the leg elastic members 48 may cause the containmentbeams 50 to pivot away from the interior surface 46 of the garment shell45.

The garment shell 45 defines an acquisition zone 78 (FIGS. 1, 5 and 6)which is the region of the garment shell that is likely to directlyreceive insults of liquid. For purposes of the present invention, theacquisition zone 78 shall be considered to consist of the centralone-third of the garment shell 45 in the longitudinal direction 22 andthe central one-third of the garment shell in the transverse direction24, measured while the garment shell is in a stretched and laid flatposition. In the illustrated embodiment, the acquisition/distributionmaterial 51 covers the interior surface 46 of the garment shell 45 inthe acquisition zone 78.

In one aspect of the invention, the undergarment 20 tends to form abucket shape (FIG. 5) with the containment beams 50 located along thesidewalls of the bucket and forming an inwardly-extending lip of thebucket. The acquisition/distribution material 51 in the acquisition zone78 forms the bottom of the bucket. The containment beams 50 aredesirably located in the transverse direction 24 between the acquisitionzone 78 and the first and second side edges 28 and 29. Moreparticularly, the attachment edges 62 of the containment beams 50 aredesirably bonded to the interior surface 46 at a transverse locationoutward of the acquisition zone 78 and at or inward of the position ofthe leg elastic members 48. Specifically, the attachment edges 62 of thecontainment beams 50 are desirably located between 0 to about 5 cm fromthe leg elastic members 48, and more desirably between 0 to about 2.5 cmfor improved performance. By positioning the containment beams 50 in theouter transverse thirds of the garment shell 45, the containment beamstend to form part of the sidewalls of the bucket shape. Additionally,the acquisition zone 78 is desirably more flexible than the outertransverse thirds of the garment shell 45. As a result of the greaterflexibility of the acquisition zone 78 and the use of separate,independent containment beams 50, the garment shell 45 tends to forminflection points 79 between the inner containment beams 50A and 50B.The containment beams 50 are located transversely outward of theinflection points 79 forming the sidewalls of the bucket shape, and theacquisition zone 78 is located between the inflection points forming thebottom of the bucket shape.

In another aspect of the invention, the acquisition zone 78 (FIGS. 5 and6) of the undergarment 20 provides void space to rapidly take inmultiple insults of liquid. FIG. 6 shows a transverse section view ofthe undergarment 20 similar to FIG. 5, but illustrating the position ofthe containment beams 50 after the undergarment has absorbed an insultof liquid. Insults of liquid tend to be quickly taken up by theacquisition/distribution material 51 and subsequently desorbed by theabsorbent structures 52 of the containment beams 50. Consequently, thecontainment beams 50 may tend to swell as illustrated in FIG. 6. Theacquisition zone 78 and the region between the containment beams 50continue to provide void space to accept additional insults of liquid.Further, the partially or fully swollen containment beams 50 tend tofunction at least in part as physical barriers to lateral liquid flow.

The undergarment 20 may be constructed so that the acquisition zone 78has a saturated liquid retention capacity that is from 0 to about 50percent, such as from 0 to about 30 percent, of the total saturatedliquid retention capacity of the undergarment. More desirably, tomaintain the void volume of the acquisition zone 78, the undergarment 20is constructed so that the acquisition zone comprises less than about 10percent, and even more desirably less than about 5 percent, of the totalsaturated retention capacity of the undergarment. By way ofillustration, an acquisition zone 78 in an undergarment 20 adapted foruse by moderately incontinent adults may have a saturated retentioncapacity of from about 30 to about 50 grams.

The saturated retention capacity of the acquisition zone 78 and theremaining portions of the undergarment can be determined by cutting theacquisition zone from the undergarment, measuring the saturatedretention capacity of both, and comparing the value obtained for justthe acquisition zone to the total value of the acquisition zone and theremaining portions. It should be understood that the free edges 63 ofthe containment beams 50 may be positioned over the acquisition zone 78but do not form part of the acquisition zone if the attachment edges 62are bonded to the interior surface 46 transversely outward from theacquisition zone. The saturated retention capacity of the acquisitionzone 78 and the remaining portions of the undergarment can be determinedaccording to the Saturated Retention Capacity Test as set forth in theTEST PROCEDURES section below. In particular embodiments, theundergarment 20 is constructed so that the containment beams 50 comprisefrom about 50 to 100 percent of the saturated liquid retention capacityof the undergarment, and more particularly from about 90 to 100 percentfor improved performance.

An alternative undergarment 80 according to the present invention isillustrated in FIGS. 7 and 8, where components similar to thosepreviously described have been given the same reference numeral. Theundergarment 80 includes first and second inner liquid containment beams50A and 50B and first and second outer liquid containment beams 50C and50D, all bonded to the interior surface 46 of a garment shell 45. Anacquisition/distribution material 51 is positioned between the innerliquid containment beams 50A and 50B, and longitudinal end seals 68 maybe provided to tack down the longitudinal ends 60 of the containmentbeams 50.

The garment shell 45 includes a bodyside liner 44 and a moisture barrier40, the latter of which may comprise a liquid impermeable inner layer 82and a soft outer layer 83. In one particular embodiment, the inner layer82 comprises a cast or blown film formed of polypropylene, polyethyleneor the like, and the outer layer 83 comprises a spunbond web formed ofpolypropylene and polyethylene medium-crimped bicomponent fibers in a50/50 side-by-side configuration. The inner and outer layers 82 and 83may be bonded together such as by a patterned application of adhesive,by thermal bonds, or other suitable means.

The garment shell 45 of the undergarment 80 also includes optionalsupplemental absorbent assemblies 84 disposed between the bodyside liner44 and the moisture barrier 40. The supplemental absorbent assemblies 84are desirably positioned between the acquisition zone 78 and the frontand back end edges 26 and 27 of the garment shell 45 to improve fit,comfort and liquid absorbency in the front and back waist regions 30 and32. Alternatively, the supplemental absorbent assemblies 84 may also bedisposed in the crotch region 34 of the undergarment 80. Thesupplemental absorbent assemblies 84 may be formed of layers of tissue,wood pulp fluff, or other absorbent materials such as those describedabove in relation to the absorbent structures 52 of the containmentbeams 50. Elastic members such as leg elastic members 48 are alsodesirably bonded between the bodyside liner 44 and the moisture barrier40. To enhance the ability of the elastic members 48 to shape theundergarment 20, the supplemental absorbent assemblies 84 are desirablynot attached directly to, and therefore uncoupled from, the containmentbeams 50.

As best illustrated in FIG. 8, each of the containment beams 50 includesa plurality of individual absorbent structures 52 within a support layer54. The individual absorbent structures 52 within each containment beam50 are in a shingled arrangement, wherein the individual absorbentstructures are positioned on top of one another but also offset from oneanother in the transverse direction 24. This shingled arrangement of theabsorbent structures 52 within each of the containment beams 50, as wellas the shingled arrangement of the outer containment beams 50C and 50Dover the inner containment beams 50A and 50B, provides a gradualincrease and then decrease in thickness of the undergarment 80 in thetransverse direction 24, for improved comfort. The illustratedcontainment beams 50 include three individual absorbent structures 52per containment beam, although the particular number may vary.Alternatively, a single absorbent structure 52 having a graduallyincreasing and then decreasing thickness profile in the transversedirection 24 may be used (not shown).

The undergarment 80 also includes leakage barriers 86 that are bonded tothe top surface 64 of the outer containment beams 50C and 50D to inhibitlateral migration of liquids and present a dry surface against the legsof the wearer. The leakage barriers 86 may be formed of any soft, liquidimpermeable material. For example, the leakage barriers may comprise atwo layer adhesive composite consisting of a liquid impermeable layer 87and a soft nonwoven layer 88. In one embodiment, the leakage barriers 86comprise an adhesive laminate of a 17 gsm (0.5 osy) 2.5 denier spunbondpolypropylene and a 0.01 millimeter polyolefin based film. As shown inFIG. 8, portions of the leakage barriers 86 may extend transverselyoutward of the outer containment beams 50C and 50D and be bonded to theinterior surface 46, inward of the side edges 28 and 29. The leakagebarriers 86 may be bonded to the containment beams 50 and the interiorsurface 46 using adhesives, ultrasonic bonds, thermal bonds, mechanicalbonds, or other suitable means.

A further alternative construction of an undergarment 90 according tothe present invention is partially illustrated in FIG. 9. Theundergarment 90 includes a bodyside liner 44 bonded to a moisturebarrier 40, with leg elastic members 48 positioned therebetween. Themoisture barrier 40 desirably comprises a vapor permeable andsubstantially liquid impermeable material. Alternatively, the moisturebarrier 40 may comprise several regions with at least one region beingvapor permeable and substantially liquid impermeable.

The moisture barrier 40 suitably comprises, for example, a materialhaving a water vapor transmission rate (WVTR) value of at least about100 grams per square meter per 24 hours (gm/m² /24 hr). Moreparticularly, the moisture barrier 40 comprises a material having a WVTRvalue of at least about 2,000 gm/m² /24 hr, and more desirably having aWVTR of at least about 3,000 gm/m² /24 hr, for improved performance. Onesuitable procedure for measuring the WVTR value of a material is setforth in the TEST PROCEDURES section below. The moisture barrier 40 maycomprise, for example, any micro-porous, "breathable" material whichpermits gases, such as water vapor, to escape while substantiallypreventing liquid exudates from passing therethrough. Suitablebreathable materials include a microporous polymer film or a nonwovenfabric which has been coated or otherwise treated to impart a desiredlevel of liquid impermeability, or the like. For example, a suitablemicroporous film is available under the trade designation PMP-1 fromMitsui Toatsu Chemicals, Inc., a company having offices in Tokyo, Japan;or a polyolefin film available under the trade designation XK0-8044 from3M Company of Minneapolis, Minn., U.S.A.

The undergarment 90 also includes desiccant particles 92 positionedbetween the moisture barrier 40 and the bodyside liner 44. The desiccantparticles 92 minimize the formation of condensation which may tend toform on the exterior surface 47 of the breathable moisture barrier 40.The desiccant particles 92 may be wrapped in an envelope 94 comprising,for example, a nonwoven web such as a tissue or spunbond material.Alternatively or in addition thereto, the desiccant particles 92 may beheld in place with adhesives or other components (not shown). Theundergarment 90 also includes an acquisition/distribution material 51,and the desiccant particles may alternatively be positioned between thebodyside liner 44 and the acquisition/distribution material. Desiccantparticles 92 suitable for use in the undergarment 90 include calciumchloride, calcium oxide, superabsorbent materials, silica gel, or thelike. In one embodiment, an envelope 94 is formed by two layersmeasuring 10.16 by 40.64 centimeters which are bonded together and 1.0gram of calcium oxide (CaO) is evenly distributed between the layers.Each layer comprises a 13.5 gsm (0.4 osy) point bonded web formed of 50percent polyethylene sheath/50 percent polypropylene core 2.6 denierbicomponent fibers.

To further minimize the potential formation of condensation on the outersurface of the breathable moisture barrier 40, the undergarment 90 isprovided with leakage barriers 86 at least partially positioned betweenthe containment beams 50 and the moisture barrier. The leakage barriers86 will thus tend to isolate the absorbent structures 52 of thecontainment beams 50 from the moisture barrier 40, as well as inhibitinglateral migration of liquids and providing a dry surface against thelegs of the wearer. The leakage barriers 86 desirably have a baseportion 96 bonded to the moisture barrier 40 and an exposed portion 97bonded to the top surface of at least the outer containment beams 50Cand 50D. As illustrated, the exposed portion 97 extends inward asufficient distance so that it is positioned against and bonded to atleast a portion of the top surface 64 of each inner containment beam 50Aand 50B as well.

The undergarment 90 may optionally be provided with a distribution layer98 to promote liquid movement from the acquisition/distribution material51 to the containment beams 50. The distribution layer 98 is desirablybonded onto the base portion 96 of the leakage barriers 86 usingadhesives, ultrasonic bonds, thermal bonds, mechanical bonds or othersuitable means. The distribution layer 98 is positioned on top of thebase portion 96 so that it is in liquid communication with thecontainment beams 50. The attachment edges 62 of the containment beams50 are then bonded to the distribution layer 98. Most desirably, theinner portion of the distribution layer 98 overlaps the outer portion ofthe acquisition/distribution material 51 so that the distribution layerand acquisition/distribution material are in liquid communication.

The distribution layer 98 may comprise any material that directs liquidflow in one or more directions in the plane defined by the length andwidth of the distribution layer. The distribution layer 98 is suitably anonwoven web made of cellulosic fibers or thermoplastic fibers, such aspolyethylene, polypropylene, polyester, or the like, and can be formedas a bonded carded web, a meltblown web, a spunbonded web, or blendsthereof. In one specific embodiment, the distribution layer 98 comprisesa 75 gsm (2.2 osy) hydroentangled pulp sheet made with soft wood pulpavailable from Kimberly-Clark Corporation of Neenah, Wis., U.S.A. underthe trade designation Longlac 19. The pulp sheet includes 1 weightpercent surfactant available from Witco Chemical Corporation, OrganicsDivision, of Melrose, Ill., U.S.A. under the trade designation AROSURF®PA727. The distribution layer 98 may alternatively comprise slivers,sliver-like materials, sulfonated pulps, or the like.

Another alternative construction of an undergarment 100 according to thepresent invention is partially illustrated in FIG. 10. The undergarment100 includes a bodyside liner 44 bonded to a moisture barrier 40, withcontainment beams 50, acquisition/distribution material 51, and legelastic members 48 all disposed between the bodyside liner and themoisture barrier. The bodyside liner 44 is desirably bonded directly tothe moisture barrier 40 and acquisition/distribution material 51, butneed not be bonded directly to the containment beams 50 to allow formovement of the containment beams.

The containment beams 50 of the undergarment 100 consist of absorbentstructures 52 and do not include support layers 54 as illustrated in theprevious embodiments. The absorbent structures 52 desirably havesufficient integrity to be bonded along their attachment edges 62 to themoisture barrier 40 and to remain an integral structure even afterabsorbing liquid. For example, the absorbent structures may comprise acoform material formed of a matrix of thermoplastic polymer fibers andindividualized wood pulp fibers disposed throughout the matrix. Suitablecoform materials are disclosed in U.S. Pat. No. 4,100,324 issued Jul.11, 1978, to Anderson et al.; U.S. Pat. No. 4,604,313 issued Aug. 5,1986, to McFarland et al.; and U.S. Pat. No. 5,350,624 issued Sep. 27,1994, to Georger et al.; the disclosures of which are incorporatedherein by reference. Particularly where the containment beams 50 arebonded to the moisture barrier 40 in the manner illustrated in FIG. 10,it will be apparent that a portion of the absorbent structure 52 remotefrom the free edge 63 may optionally not be bonded directly to themoisture barrier 40, provided the containment beam has a portionfunctioning as an attachment edge and the free edge is moveable relativeto the garment shell 45. Because the bodyside liner 44 is positionedover the containment beams 50, the liner is not considered to form partof the garment shell 45 in this embodiment.

A still further alternative undergarment 110 according to the presentinvention is illustrated in FIGS. 11 and 12. The undergarment 110includes a garment shell 45 with a bodyside liner 44 bonded to amoisture barrier 40, and leg elastic members 48 positioned therebetween.First and second containment beams 50A and 50B are bonded to theinterior surface 46 of the garment shell 45, with anacquisition/distribution assembly 112 positioned between the containmentbeams. The acquisition/distribution assembly 112 comprises an inneracquisition/distribution material 51 and an outeracquisition/distribution liner 114.

The acquisition/distribution liner 114 includes a facing layer 116 thatis folded and bonded to itself to form a pair of peaks 118 that areseparated by a channel 120 (FIG. 12). The facing layer 116 may be formedof a wide variety of liquid permeable materials, including but notlimited to woven materials such as cloth, knit materials, permeablefilms, foams and fibrous nonwoven materials. In one particularembodiment, the facing layer 116 comprises a single layer constructionmade from a 20.3 gsm (0.6 osy) thermally bonded carded web materialutilizing 100 percent 3 denier bicomponent staple fibers from BASFCorporation. The fibers are 38 millimeters (mm) (1.5 in) in length andcomprise a polyethylene sheath surrounding a polyester core. Onesuitable acquisition/distribution material 51 comprises a single layerstructure, such as a 20.3 gsm (0.6 osy) through-air bonded carded webmade completely from 1.8 denier polyethylene sheath/polypropylene corebicomponent fibers having a length of 38 mm (1.5 in) and available fromBASF Corporation.

A filler 122 formed of a resilient, liquid permeable material is foldedupon itself and disposed within the peaks 118. In one embodiment, thefiller 122 comprises strips of a 85 gsm (2.5 osy) bonded carded webincluding 60 weight percent 3 denier polyethylene sheath/polyester corebicomponent staple fibers available from BASF Corporation under thetrade designation CS-2 and 40 weight percent 6 denier rayon fibersavailable from Courtaulds Fibers, Inc. of Axis, Ala., U.S.A. Facinglayers 116 of the foregoing type are disclosed in U.S. patentapplication Ser. No. 169,449 by M. Weber et al., filed Dec. 17, 1993,and titled "Liquid Absorbent Material For Personal Care AbsorbentArticles And The Like" (Attorney Docket No. 10,880), the disclosure ofwhich is incorporated herein by reference.

The containment beams 50A and 50B of the undergarment 110 each comprisea pair of absorbent structures 52 wrapped in a common support layer 54.The absorbent structures 52 are somewhat offset in the transversedirection 24 so as to be in a shingled relationship.

The undergarment 110 also includes end seals 68 to maintain thelongitudinal ends 60 of the containment beams 50 against the interiorsurface 46 of the garment shell 45 and to provide a physical barrier tolongitudinal movement of liquid. In this particular embodiment, the endseals 68 are formed of an elastomeric material and have integral firstand second portions 124 and 126 adjacent the opposite longitudinal edgesof the end seal. The first portions 124 are positioned closer to thetransverse center line 24 of the undergarment 110 and are desirablyunadhered to the interior surface 46. In contrast, the second portions126 are positioned further from the transverse center line 24 and aredirectly bonded to the interior surface 46. In this way, the firstportions 124 tend to stand up from the interior surface 46 and formlongitudinal liquid barriers when the end seals 68 are allowed tocontract. The end seals 68 desirably do not substantially gather thegarment shell 45 in the transverse direction 24.

Containment beams 50 as described in relation to the foregoingembodiments may also be employed on other disposable absorbent products.Examples of such products, for instance, are disclosed in U.S. patentapplication Ser. No. 08/168,615 by T. Roessler et al., filed Dec. 16,1993, and titled "Dynamic Fitting Diaper" (Attorney Docket No. 10,961);U.S. patent application Ser. No. 08/168,615 by E. D. Johnson et al.,filed Aug. 12, 1994, and titled "Diaper With Improved Lateral ElongationCharacteristics" (Attorney Docket No. 11,629); and U.S. Pat. No.4,940,464 issued Jul. 10, 1990, to P. Van Gompel et al.

The following EXAMPLES are provided to give a more detailedunderstanding of the invention. The particular amounts, proportions,compositions and parameters are meant to be exemplary, and are notintended to specifically limit the scope of the invention.

TEST EXAMPLE 1

A number of test undergarments representing one embodiment of thepresent invention were constructed. These test undergarments included amoisture barrier formed of a polyethylene film and measuring 68.6 by22.1 cm. Leg elastic members were operatively joined to the moisturebarrier along the two side margins in the crotch region of the garment.

The test undergarments included two containment beams each measuring54.6 cm long, 3.2 cm wide, and 1 cm thick. Each containment beamincluded three identical absorbent structures stacked on top of oneanother. The absorbent structures were formed of a mixture of 50 weightpercent wood pulp fluff and 50 weight percent superabsorbent particles.The absorbent structures were substantially fully wrapped in a singlesupport layer formed of a 20 gsm thermally bonded carded web ofpolyethylene sheath and polyester core bicomponent fibers from BASFCorporation, which were treated with 1.5 weight percent surfactantavailable from Union Carbide Chemicals and Plastics Company, Inc. underthe trade designation Triton X-102. The support layer was bonded to themoisture barrier so that each containment beam was pivotable about anaxis defined by its attachment edge. The containment beams were curvedslightly so that the free edges of the containment beams were spacedapart by about 4 cm at their longitudinal center and spaced apart byabout 7 cm at their longitudinal ends. The containment beams weregenerally centered in the longitudinal direction of the undergarment andspaced from the leg elastic members by about 2.5 cm. The two containmentbeams had a combined saturated retention capacity of about 450 grams.

An acquisition/distribution assembly was positioned between thecontainment beams and bonded to the support layer. Theacquisition/distribution assembly comprised an acquisition/distributionmaterial disposed on and bonded to the support layer between thecontainment beams. The acquisition/distribution material measured 54.6cm long and 10.2 cm wide and comprised a 50 gsm spunbond web formed ofside-by-side polypropylene/polyethylene bicomponent fibers.

The acquisition/distribution assembly also included anacquisition/distribution liner similar to that illustrated in FIGS. 11and 12. The acquisition/distribution liner measured 25.4 by 10.2 cm andwas bonded onto the acquisition/distribution material. Theacquisition/distribution liner included a facing layer that was foldedand bonded to itself to form a pair of peaks that were separated by achannel. A filler was positioned in the peaks, and the facing layer wasbonded to a backing layer.

The facing and backing layers each comprised of a single layerconstruction made from a 20.3 gsm thermally bonded carded web materialutilizing 100 percent 3 denier bicomponent staple fibers from BASFCorporation. The fibers, which were 38 mm in length and comprised apolyethylene sheath surrounding a polyester core, were treated with 1.5weight percent surfactant available from Union Carbide Chemicals andPlastics Company, Inc. under the trade designation Triton X-102. Thefiller comprised strips of an 85 gsm bonded carded web including 60weight percent 3 denier polyethylene sheath/polyester core bicomponentstaple fibers available from BASF Corporation under the tradedesignation CS-2 and 40 weight percent 6 denier rayon fibers availablefrom Courtaulds Fibers, Inc. of Axis, Ala., U.S.A.

The acquisition/distribution assembly also included two relativelynarrow strips of acquisition/distribution material disposed between theacquisition/distribution liner and the 54.6 by 10.2 cm layer ofacquisition/distribution material. The strips, which were stacked on topof one another, measured 25.4 by 2.5 cm and 25.4 by 5.1 cm. The stripswere formed of the same material as the 54.6 by 10.2 cm layer ofacquisition/distribution material.

The acquisition zone of the undergarment, defined as the central onethird of the garment shell in the longitudinal direction and the centralone third of the garment shell in the transverse direction, comprisedless than 5 percent of the total saturated retention capacity of theundergarment.

The test undergarments also included a single peak structure positionedbetween each containment beam and each set of the leg elastic members.Each peak structure was identical in construction and materials as thepeaks formed in the acquisition/distribution liner. The peak structuresoutward of the containment beams, however, were 35.6 cm long, whereasthe peaks of the acquisition/distribution liner were only 25.4 cm long.

End seals formed of a liquid impermeable material and measuring 2.5 by15.2 cm were positioned over the longitudinal ends of the containmentbeams and bonded to the support layer. Additionally, a bodyside linermaterial was bonded to the moisture barrier in locations not covered bythe support layer. The bodyside liner comprised a 20 gsm spunbond webformed of polypropylene fibers.

The fastening system for the test undergarments included two strapmembers that were formed of an elastic material purchased from ShelbyElastics of Shelby, N.C., U.S.A. The strap members had a length of about26 cm and a width of about 2.5 cm. Buttons were attached near each endof each strap member, and reinforced buttonholes were formed on eachundergarment.

COMPARATIVE EXAMPLE 1

The undergarments of Test Example 1 were evaluated relative tocomparative undergarments corresponding to undergarments of the typesold in about August of 1994 by Kimberly-Clark Corporation under thetradename Depend®. The comparative undergarments included a moisturebarrier, leg elastic members, and a fastening system similar to thoseused in the test undergarments.

A generally planar absorbent assembly was disposed on the moisturebarrier. The absorbent assembly measured 59.4 by 14.5 cm and was formedof cellulose fluff, sprayed polypropylene filaments, and superabsorbentparticles. The absorbent assembly was wrapped in tissue and the tissuewas attached to the moisture barrier using a construction adhesive. Abodyside liner was disposed on the absorbent assembly and bonded to themoisture barrier outward of the absorbent assembly. The bodyside linercomprised a 20 gsm spunbond polypropylene web that was treated with 1.5weight percent surfactant available from Union Carbide Chemicals andPlastics Company, Inc. under the trade designation Triton X-102. Thecomparative undergarments had a saturated retention capacity of about450 grams.

For purposes of analyzing the performance of the undergarments of TestExample 1, a forced failure test was conducted. The test used 36participants including 18 men and 18 women. The participants were eachfitted with an apparatus that included a flexible tube having an exitend positioned in the crotch region. Each participant was asked to weareither the Test Example 1 undergarment or the Comparative Example 1undergarment, selected randomly, under an appropriately sized pair ofunderwear. After the participant wore the undergarment for 30 minutes,the participant was seated and the undergarment was then loaded throughthe tube with three insults of 24 milliliters (ml) of 0.9 percent salinesolution spaced 60 seconds apart. Two minutes later, the participantrose to a standing position while a gush of 72 ml of saline solution wasinfused into the tube. The participant remained standing for two minutesafter which time the participant was seated. Additional insults of 24 mlof saline solution were loaded through the tube at 60 second intervalsuntil leakage occurred. This procedure was repeated so that eachparticipant tested each of the Test Example 1 undergarments and each ofthe Comparative Example 1 undergarments twice.

The undergarments of Test Example 1 were found to have absorbed anaverage of about 186.85 grams of liquid at the point of leakage comparedto an average of about 146.49 grams of liquid at the point of leakagefor the undergarments of Comparative Example 1. Table 1 below shows theaverage loading value at the point of leakage for each participant forthe two Test Example 1 undergarments and the two Comparative Example 1undergarments. The average and standard deviation values were calculatedfrom the individual observed values rather than the mean values shown inthe table.

                  TABLE 1    ______________________________________             COMPARATIVE             EXAMPLE 1        TEST EXAMPLE 1    Participant               Mean    Std Dev    Mean  Std Dev    ______________________________________    1          107.50  20.51      195.50                                        20.51    2          164.50  3.54       175.50                                        9.19    3          127.00  18.38      127.50                                        43.13    4          117.50  28.99      117.00                                        28.28    5          94.00   2.83       95.00 1.41    6          118.00  4.24       184.00                                        36.77    7          134.50  48.79      202.00                                        16.97    8          191.50  30.41      181.50                                        17.68    9          177.00  14.14      179.50                                        50.20    10         121.50  0.71       178.50                                        16.26    11         134.00  49.50      215.50                                        31.82    12         177.00  15.56      227.50                                        14.85    13         131.50  16.26      156.50                                        14.85    14         109.50  14.85      253.50                                        45.96    15         103.50  17.68      249.00                                        46.67    16         224.00  8.49       250.50                                        13.44    17         212.00  28.28      195.00                                        70.71    18         181.50  21.92      279.00                                        57.98    19         131.00  21.21      226.50                                        14.85    20         143.50  4.95       217.00                                        39.60    21         141.50  64.35      283.00                                        35.36    22         168.00  1.41       262.00                                        36.77    23         164.00  25.46      167.50                                        4.95    24         203.00  14.14      266.00                                        36.77    25         112.00  33.94      121.50                                        34.65    26         119.00  103.24     191.50                                        106.77    27         176.50  20.51      164.00                                        25.46    28         215.50  4.95       137.50                                        68.59    29         165.50  4.95       238.50                                        3.54    30         190.00  7.07       192.00                                        5.66    31         117.50  41.72      136.00                                        73.54    32         121.50  28.99      176.50                                        113.84    33         120.00  2.83       167.50                                        2.12    34         137.50  53.03      129.00                                        41.01    35         117.50  31.82      97.00 0.00    36         104.00  18.38      91.00 4.24    Average    146.49  42.02      186.85                                        61.07    ______________________________________

TEST EXAMPLE 2

A number of test undergarments having the general configuration of theundergarment 110 shown in FIGS. 11-12 were also constructed. Theundergarments of Test Example 2 included a bodyside liner, end seals,leg elastic members, and a fastening system similar to those used in theundergarments of Test Example 1. The undergarments of Test Example 2 didnot include the single peak structures between the containment beams andleg elastic members as were used in the undergarments of Test Example 1.

The undergarments of Test Example 2 included a moisture barriercomprised of an adhesive laminate of an inner layer and an outer layer.The inner layer comprised a liquid and vapor impermeable polyethylenefilm, and the outer layer comprised a point bonded spunbond nonwovenformed of polypropylene and polyethylene medium-crimped bicomponentfibers in a 50/50 side-by-side configuration. The moisture barriermeasured 68.6 by 22.1 cm.

The undergarments of Test Example 2 included two containment beams eachmeasuring 44.5 cm long, 3.2 cm wide, and 1 cm thick. Each containmentbeam included two identical absorbent structures slightly offset in thetransverse direction so as to be in a shingled configuration (see FIG.12). The absorbent structures were formed of a mixture of 80 weightpercent wood pulp fluff and 20 weight percent superabsorbent particles.The absorbent structures were substantially fully wrapped in a singlesupport layer formed of a 20 gsm thermally bonded carded web ofpolyethylene sheath and polyester core bicomponent fibers from BASFCorporation, which were treated with 1.5 weight percent surfactantavailable from Union Carbide Chemicals and Plastics Company, Inc. underthe trade designation Triton X-102. The support layer was bonded to themoisture barrier so that each containment beam was pivotable about anaxis defined by its attachment edge. The containment beams were curvedslightly so that the distance between the free edges varied betweenabout 5 and about 7 cm. The containment beams were skewed toward thefront end edge of the undergarment and spaced from the leg elasticmembers by about 2.5 cm. The two containment beams had a combinedsaturated retention capacity of about 260 grams.

An acquisition/distribution assembly measuring 25.4 by 10.2 cm waspositioned between the containment beams and bonded to the supportlayer. The acquisition/distribution assembly comprised anacquisition/distribution liner similar to that employed in theundergarments of Test Example 1. The acquisition/distribution linermeasured 25.4 by 10.2 cm and was positioned between the containmentbeams and bonded to the support layer. The acquisition/distributionliner included a facing layer that was folded and bonded to itself toform a pair of peaks that were separated by a channel. A filler waspositioned in the peaks, and the facing layer was bonded to a backinglayer. The materials used to form the facing and backing layers and thefiller were the same as in the undergarments of Test Example 1.

The acquisition/distribution assembly also included two relativelynarrow strips of acquisition/distribution material disposed between theacquisition/distribution liner and the support layer. The strips, whichwere stacked on top of one another, measured 25.4 by 2.5 cm and 25.4 by5.1 cm. The strips comprised a 50 gsm spunbond web formed ofside-by-side polypropylene/polyethylene bicomponent fibers.

The acquisition zone of the undergarment, defined as the central onethird of the garment shell in the longitudinal direction and the centralone third of the garment shell in the transverse direction, comprisedless than 5 percent of the total saturated retention capacity of theundergarment.

COMPARATIVE EXAMPLE 2

Comparative undergarments similar to those of Comparative Example 1 werealso provided for purposes of evaluation. The undergarments ofComparative Example 2, however, were modified as follows. First, thetissue did not completely wrap the absorbent assembly so that a middleportion of one surface of the absorbent assembly was directly bonded tothe moisture barrier using a construction adhesive. Second, the bodysideliner was directly bonded to the tissue using a construction adhesive.And third, the undergarments of Comparative Example 2 included anacquisition/distribution material measuring 25.4 by 10.2 cm. Theacquisition/distribution material, which comprised a 75 gsm bondedcarded web formed of polyethylene fibers, was bonded to the side of thebodyside liner facing the moisture barrier using a constructionadhesive.

The performance of the undergarments of Test Example 2 and theundergarments of Comparative Example 2 was compared in a forced failureevaluation. This forced failure evaluation utilized 36 participantsincluding 18 men and 18 women. The participants were each fitted with anapparatus that included a flexible tube having an exit end positioned inthe crotch region. Each participant was asked to wear either the TestExample 2 undergarment or the Comparative Example 2 undergarment,selected randomly, under an appropriately sized pair of underwear. Theundergarment was then loaded through the tube with an initial load of100 ml of 0.9 percent saline solution while the participant wasstanding. After 30 minutes of wear time and in increments of 5 minutesthereafter, subsequent loads of 24 ml of saline solution were loadedthrough the tube while the participant was sitting, until leakageoccurred. This procedure was repeated so that each participant testedeach of the Test Example 2 undergarments and each of the ComparativeExample 2 undergarments twice.

The undergarments of Test Example 2 were found to have absorbed anaverage of about 390.50 grams of liquid at the point of leakage comparedto an average of about 151.88 grams of liquid at the point of leakagefor the undergarments of Comparative Example 2. Table 2 below shows theaverage loading value at the point of leakage for each participant ofthe two Test Example 2 undergarments and the two Comparative Example 2undergarments. The average and standard deviation values were calculatedfrom the individual observed values rather than the mean values shown inthe table. Participants 13, 17, 22, 30 and 35 only tested one of theTest Example 2 undergarments.

                  TABLE 2    ______________________________________             COMPARATIVE             EXAMPLE 2        TEST EXAMPLE 2    Participant               Mean    Std Dev    Mean  Std Dev    ______________________________________    1          127.00  2.83       442.50                                        61.52    2          107.50  16.26      308.50                                        60.10    3          155.00  63.64      505.50                                        34.65    4          172.00  4.24       394.00                                        16.97    5          149.00  72.12      315.00                                        91.92    6          168.50  2.12       395.00                                        65.05    7          164.50  0.71       480.00                                        121.62    8          180.67  32.33      354.00                                        308.30    9          241.00  69.30      356.50                                        111.02    10         174.00  12.73      398.50                                        152.03    11         180.00  46.67      476.00                                        39.60    12         137.00  16.97      410.00                                        5.66    13         131.00  24.04      342.00                                        .    14         96.00   1.41       313.00                                        32.53    15         104.50  2.12       335.00                                        69.30    16         99.50   2.12       215.50                                        26.16    17         126.50  34.65      233.00                                        .    18         150.50  2.12       269.00                                        60.81    19         170.00  2.83       339.00                                        134.35    20         202.00  15.56      635.00                                        31.11    21         152.50  48.79      525.50                                        89.80    22         168.00  70.71      507.00                                        .    23         152.00  63.64      446.00                                        24.04    24         209.50  14.85      474.00                                        .    25         116.00  16.97      361.00                                        39.60    26         107.00  18.38      323.00                                        60.81    27         110.00  14.14      278.50                                        19.09    28         117.50  28.99      357.00                                        14.14    29         126.00  39.60      296.50                                        85.56    30         164.00  31.11      505.00                                        .    31         182.50  10.61      487.50                                        31.82    32         196.50  43.13      474.50                                        55.86    33         167.00  1.41       497.50                                        21.92    34         154.00  0.00       411.00                                        28.28    35         163.00  32.53      292.00                                        .    36         131.50  14.85      310.00                                        8.49    Average    151.88  41.03      390.50                                        110.29    ______________________________________

Several participants noted that the undergarments of Test Example 2 wereless bulky than the undergarments of Comparative Example 2.Additionally, several participants noted that the undergarments of TestExample 2 did not feel uncomfortable in either the dry or wet state. Itis hypothesized that the undergarments of Test Example 2 had a greateraverage loading value at the point of leakage compared to theundergarments of Test Example 1 because the containment beams of TestExample 2 provided greater open spaces for liquid to reside.

Test Procedures

Saturated Retention Capacity

The saturated retention capacity of a material is measured as follows.The material to be tested, having a moisture content of less than about7 weight percent, is weighed and submerged in an excess quantity of roomtemperature (about 23 degrees Celsius) synthetic urine. The material tobe tested is allowed to remain submerged for 20 minutes. After 20minutes, the material is removed from the urine and placed on a Teflon™coated fiberglass screen having 0.25 inch openings (commerciallyavailable from Taconic Plastics Inc., Petersburg, N.Y.) which, in turn,is placed on a vacuum box and covered with a flexible rubber dammaterial. A vacuum of 3.5 kilopascals (0.5 pounds per square inch) isdrawn in the vacuum box for a period of 5 minutes. The material isweighed. The amount of fluid retained by the material being tested isdetermined by subtracting the dry weight of the material from the wetweight of the material (after application of the vacuum) and is reportedas the saturated retention capacity in grams of fluid retained. Forrelative comparisons, this value can be divided by the weight of thematerial to give the saturated retention capacity in grams of fluidretained per gram of tested material.

The synthetic urine composition referenced herein comprises 0.31 gramsmonobasic calcium phosphate monohydrate (CaH₄ (PO₄)₂ H₂ O), 0.68 gramsmonobasic potassium phosphate (KH₂ PO₄), 0.48 grams magnesium sulphateheptahydrate (MgSO₄ 7H₂ O), 1.33 grams potassium sulphate (K₂ SO₄), 1.24grams tribasic sodium phosphate dodecahydrate (Na₃ PO₄ 12H₂ O), 4.4grams sodium chloride (NaCl), 3.16 grams potassium chloride (KCl), 8.56grams of urea (CO(NH₂)₂), 0.1 grams Pluronic 10R8 surfactant (anon-ionic surfactant commercially available from BASF-WyandotteCorporation) and 1 gram methyl paraben and 1 gram Germall 115preservative (commercially available from Santell Chemical Company,Chicago, Ill.) per liter using distilled water as the solvent. Thecomponents are added to 900 milliliters of distilled water in the ordergiven and each dissolved before the next component is added. Thesolution is finally diluted to one liter.

If material, such as high-absorbency material or fiber is drawn throughthe fiberglass screen while on the vacuum box, a screen having smalleropenings should be used. Alternatively, a piece of tea bag material canbe placed between the material and the screen and the final valueadjusted for the fluid retained by the tea bag material. Suitable teabag material is a heat sealable tea bag material grade 542, commerciallyavailable from Kimberly-Clark Corporation. The amount of fluid absorbedby the tea bag material is determined by performing the saturatedretention capacity test on an empty tea bag. Testing high-absorbencymaterials or fibers alone can be accomplished using a sealed pouch oftea bag material.

Water Vapor Transmission Rate

A suitable technique for determining the WVTR (water vapor transmissionrate) value of a material is ASTM Standard E96-80. For the purposes ofthe present invention, circular samples measuring 3 inches in diameterare cut from the test material and a control material which is a pieceof CELGUARD® 2500 film from Hoechst Celanese Corporation of Sommerville,N.J., U.S.A. CELGUARD® 2500 is a 0.0025 cm thick microporouspolypropylene film. Five samples are prepared for each material. Thetest dish is a No. 60-1 Vapometer pan distributed by Thwing-AlbertInstrument Company, Philadelphia, Pa., U.S.A. One hundred milliliters ofwater are poured into each Vapometer pan, and each of the samples of thetest material and control material are placed across the open tops ofthe individual pans. Do not apply stopcock grease unless samplecontamination can be avoided. Screw-on flanges are tightened to form aseal along the edges of the pans, leaving the associated test materialor control material exposed to the ambient atmosphere over a 6.5 cmdiameter circle having an exposed area of about 33.17 squarecentimeters. The pans are placed in a forced air oven set at 32° C.(100° F.) for 1 hour to equilibrate. The oven is a constant temperatureoven with external air circulating through it to prevent water vaporaccumulation inside. A suitable forced air oven is, for example, a BlueM Power-O-Matic 60 oven distributed by Blue M Electric Co. of BlueIsland, Ill., U.S.A. Upon completion of the equilibration, the pans areremoved from the oven, weighed and immediately returned to the oven.After 24 hours, the pans are removed from the oven and weighed again.The preliminary test WVTR value is calculated as follows:

    Test WVTR=(grams weight loss over 24 hours)×315.5 (g/m.sup.2 /24 hours)

The relative humidity within the oven is not specifically controlled.

Under predetermined set conditions of 32° C. (100° F.) and ambientrelative humidity, the WVTR for CELGUARD® 2500 has been determined to be5000 gm/m² /24 hours. Accordingly, the CELGUARD® 2500 is run as acontrol sample with each test, and the preliminary test values arecorrected to the set conditions using the following equation:

    WVTR=(Test WVTR/control WVTR)×5000 gm/m.sup.2 /24 hr.

The foregoing detailed description has been for the purpose ofillustration. Thus, a number of modifications and changes may be madewithout departing from the spirit and scope of the present invention.For instance, alternative or optional features described as part of oneembodiment can be used to yield another embodiment. Additionally, twonamed components could represent portions of the same structure.Therefore, the invention should not be limited by the specificembodiments described, but only by the claims.

We claim:
 1. A method of making absorbent article, comprising the stepsof:providing a garment shell comprising a moisture barrier and definingan interior surface; providing first and second inner liquid containmentbeams comprising an absorbent material wherein the liquid containmentbeams comprise from about 90 to 100 percent of the total saturatedretention capacity of the absorbent article; providing first and secondouter liquid containment beams, each of the inner and outer liquidcontainment beams having:longitudinal ends; opposite attachment and freeedges which extend between the longitudinal ends; and opposite top andbottom surfaces; and bonding each attachment edge of each of the innerand outer liquid containment beams to the interior surface, the bottomsurface of the inner containment beams being adapted to lie against theinterior surface, the bottom surface of each of the outer containmentbeams being adapted to lie against the top surface of one of the innercontainment beams, and each of the liquid containment beams beingadapted to pivot about an axis defined by its attachment edge and bemoveable relative to the moisture barrier.
 2. The method of claim 1,wherein the garment shell has a first waist region, a second waistregion, and a crotch region positioned between and interconnecting thefirst and second waist regions, and the crotch region includes anacquisition zone having lateral boundaries inboard of the attachmentedges of the first and second inner liquid containment beams.
 3. Themethod of claim 1, wherein the step of providing the first and secondinner containment beams comprises providing a plurality of absorbentstructures and a support layer, wrapping the plurality of absorbentstructures within the support layer, and bonding the support layer tothe interior surface.
 4. The method of claim 1, wherein the absorbentarticle has longitudinal and transverse axes, and in the transversedirection the garment shell forms first and second outer thirds and acentral third between the first and second outer thirds, the attachmentedges of the containment beams are bonded to the interior surface in thefirst and second outer thirds.
 5. The method of claim 4, wherein thecentral third of the garment shell has a saturated retention capacitythat is less than about 10 percent of the total saturated retentioncapacity of the absorbent article.
 6. The method of claim 4, wherein thecentral third of the garment shell comprises an acquisition/distributionmaterial, and each bottom surface of each inner containment beam isadapted to lie against the acquisition/distribution material.
 7. Themethod of claim 1, wherein the inner containment beams each comprise aplurality of individual absorbent structures in a shingled arrangementwithin a support layer.
 8. A method of making an absorbent articlehaving longitudinal and transverse axes, comprising the stepsof:providing a garment shell comprising a moisture barrier and definingan interior surface, the garment shell in the transverse directiondefining first and second outer thirds and a central third between thefirst and second outer thirds; providing first and second inner liquidcontainment beams comprising an absorbent material; providing first andsecond outer liquid containment beams, each of the inner and outerliquid containment beams wherein the liquid containment beams comprisefrom about 90 to 100 percent of the total saturated retention capacityof the absorbent article and having:longitudinal ends; oppositeattachment and free edges which extend between the longitudinal ends;and opposite top and bottom surfaces; and bonding the attachment edge ofeach of the inner and outer liquid containment beams to the interiorsurface in the first and second outer thirds, the bottom surface of eachof the inner containment beams being adapted to lie against the interiorsurface, the bottom surface of each of the outer containment beams beingadapted to lie against the top surface of one of the inner containmentbeams, and each of the liquid containment beams being adapted to pivotabout an axis defined by its attachment edge.
 9. A method of making anabsorbent article having longitudinal and transverse axes, comprisingthe steps of:providing a garment shell comprising a moisture barrier anddefining an interior surface, the garment shell in the transversedirection defining first and second outer thirds and a central thirdbetween the first and second outer thirds wherein the central third ofthe garment shell has a saturated retention capacity that is less thanabout 10 percent of the total saturated retention capacity of theabsorbent articles; providing first and second inner liquid containmentbeams comprising an absorbent material; providing first and second outerliquid containment beams, each of the inner and outer liquid containmentbeams having:longitudinal ends; opposite attachment and free edges whichextend between the longitudinal ends; and opposite top and bottomsurfaces; and bonding the attachment edge of each of the inner and outerliquid containment beams to the interior surface in the first and secondouter thirds, the bottom surface of each of the inner containment beamsbeing adapted to lie against the interior surface, the bottom surface ofeach of the outer containment beams being adapted to lie against the topsurface of one of the inner containment beams, and each of the liquidcontainment beams being adapted to pivot about an axis defined by itsattachment edge.
 10. The method of claim 9, further comprising disposingan acquisition/distribution material in the central third of the garmentshell, each inner containment beam being adapted to lie against theacquisition/distribution material.